Make-and-break sparking plug.



G. NAGEL.

MAKE AND BREAK SPABKING PLUG.

APPLIOATION FILED DBO. 2, 1911. 1,095,664, Patented May', 1914.

1n e m E v I. l l 1w c m @i .,z-- Q ||||.\\\\\\\i W v S -l.\\\ t.\-\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\Wi \M g d n Vc m WIT/vrssfs GUSTAV NAS-EL, F STUTTGART, GBMANY.

:aanname-BREAK srnnmne PLUG.

j Specication of Letters Patent.

Patented May 5, 1914.

V.Application led December 2, 1911. Serial No. 663,529.

Tfn-all whom it may concern:

Be it known that I, GUsTAv NAGEL, a sub-` ject of the German Emperor, residing at Seestrasse 26, Stuttgart, in the Empire of Germany, have invented new and useful Improvements in and Relating to Makeand-Break Sparking Plugs, of which the following is a specification. The make and break sparking plugs hitherto known in which the sparking has been operated by means of tappets, operated electromagnetically by solenoids or by compression pressure in the working cylinder, have always required special regulating mechanism on the outside of the machine for controlling the moment of sparking corresponding with the alteration' in speed of the engine, and have generally consisted in the arrangement of a spring serving to alter the tension on the make and break electrode. The subject of the present invention, however, relates to a make and break sparking plug which is particularly adapted for use in explosion motors of airships or motor boats, as also for automobiles and the like, and in this the regulation of the moment of sparking is absolutely automatically regulated from the increased amount of mixture and speed of the piston without requiring further controlling mechanism. This is ob tained according to the present invention in that the tappet rod must pass backward freely a certain distance before it lifts the movable spring controlled electrode from its corresponding fixed electrode. Therefore the speed aty which this tappet rod will be moved along this free path will be dependent upon the extent of compression pressure in the working cylinder and upon the mass of the tappet rod so that by selecting the correct length of path and a certain mass for the tappet rod the regulation of the sparking point will correspond to the output 0f the engine.

One construction of the present invention is illustrated on the accompanying drawing in vertical section of Which- Figure 1 shows the sparking plug out of operation. Fig; 2 shows the sparking plug in the position just before sparking, and Fig 3 shows the position just after the sparking. l

In the sparking plug casing a a xed electrode b is mounted insulated therefrom and connected with one pole of a source of electric current which works, together with the play in the sleeve a3 mounted on the casing a. AThe upper end of the electrode. c carries a plate e which acts as an abutment for the spring f of the make and break electrode c',

-while the other end of the spring f -abuts against the top of a perforated cap screwed on to the'sleeve d. A ta pet' rod h passes through 'the make `and reak electrode c and is ided by the latter and also by the top of t e cap g. It is controlled by a weak spring so that `the tappet rod h after each 'sparking' can again be brought back into its normal position for which purpose its vtension must be so slight that it will be overcome by the slightest compression pressure.

The spring f controlling the make and break electrode c' will, however, o n the other hand, be compressed at about the middle value of the compression pressure so that in the case of a slight compression it is not necessary for the tappet rodwto exert too strong a break action.

l The cap 7c of thetappet rod h lies in the hole Z formed in the casing a in the normal position of the sparking plug, the saidhole being avery little greater in diameter than the diameter of the cap [c so that in all cases an igniting mixture can pass to the ignition chamber for which purpose also the hole l is widened outward in the shape of a cone so that the mixture may more easily pass to the cap of the tappet.

In order to prevent pre-ignition and also to allow the burnt ymixture to pass freely away and not to prevent entrance of a fresh igniting mixture, the arrangement is such that the tappet rod and the make and break electrode make a tight joint between the inside of the cylinder and the place of ignition, as shown in Figs. 2 and 3, so that owing tothe compression ressure the cap 7c of the tappet rod k wil ass into the enlargement m of the electro e c (Fig. 2) and after the make and break has taken place this will lie tightly against the conical enlargement 'n of the sleeve d (Fig. 3) so that in this position no sparkin mixture whatever can pass back, While .a er the sparking has taken place the remainder` of the used mixture in the sparking chamber can easily movable .electrode "c connected to the otherL pole, which latter can slide with very little the next ignition only fresh ring mixture will be in the firing chamber. In the norler mal position of the sparking plug, therefore, owing to this packing pre-ignition is completely excluded as the guiding of the cap /t' 1,

in the hole Z during the suction period allows no further firing mixture to pass to the firing point.

rI`he mode of operation of the sparking plug according to the present invention is as follows: In the normal position of the sparking plug (Fig. l) the movable make and break electrode c is pressed against the fixed electrode b by means of the spring f tensioned to about the middle value of the compression pressure, so that the cap i: of the tappet bolt 7L will lie in the hole Z of the sparking chamber. Should the engine be set in operation then the compression pressure in the working cylinder will operate in such a manner on the cap k of the tappet rod 7L as to push this backward until it abuts against the enlargement m of the make and break electrode 0 (Fig. 2) and thus force this away from the fixed electrode b which causes the passing of a spark and in consequence the ignition of the coinpressed gas (Fig. 3). As now the piston of the working cylinder moves faster at the beginning of its stroke than it does toward the end of the latter, that is to say, as it nears the dead center (crank drive) and as further for the purpose of moving the tappet rod along its free path its mass must be overcome by the increasing compression pressure due to the movement of the piston, and accelerated in such a manner that the tappet rod is moved to the'end of its free path to overcome the spring of the make and break electrode c it results that when the speed of the working piston has increased during the movement of the tappet rod the speed of the latter will not have increased in corresponding ratio, as the in creasing compression pressure has to cause an acceleration of the 1nass,tha`t is to say,produce i work, from which it. follows therefore that according as more mixture is being passed into the engine and the speed of the latter increases, the moment of ignition can be automatically regulated, corresponding to the most favorable position of the piston by selecting the mass of the tappet rod and the length of the path along which this must freely move. As, however, the increase in speed of the engine always depends upon the amount of charge the factors necessary for determining the above values for the,

automatic regulation of 'the sparking point can be immediately found.

Such a regulating apparatus can, of course, be constructed in any other manner beside that mentioned above with reference to a make and break sparking plug 'whenever it is desired to form the moment of sparking dependent on the speed of a movable member.

What I claim is: l. In a make and break spark plug, the

i electrode' normally engaging said fixed electrode, a tappet rod movable through a pre determined path and provided with a projecting portion adapted to engage and move said movable electrode out of engagementwith said fixed electrode upon actuation of Vsaid tappet rod, said tappet rod being controlled directly by the compression of the engine, and means normallyholding said tappet rod with said projection out of engagement with said movable'electrode.

2. In a make and break spark plug, the combination of a fixed electrode, a movable electrode, a tappet rod provided with a project-ing portion adapted to engage and move said movable electrode upon actuation of said tappet rod, a spring normally holding said tappet rod with said projection out of engagement with said movable electrode, and a spring normally holding said movable electrode in engagement with said fixed electrode, said first mentioned spring being weaker than said second mentioned spring.

3. In a make and break spark plug, the combination of a base, a fixed electrode mounted thereon and insulated therefrom, a sleeve on .said base, a movable electrode guided in said sleeve, a tappet rod provided with a projecting portion adapted to engage and move said movable electrode upon actuation of said tappet rod, a spring normally holding said tappet rod with said projection out of engagement with said movablev electrode, and a spring normally holding said movable electrode in engagement with said fixed electrode, said first mentioned spring being weaker than said second mentioned spring.

4. In a make and break spark plug, the combination of a. base, a fixed electrode n'iounted thereonand insulated therefrom, a sleeve on said base, a movable electrode concentrically mounted, in said sleeve and guided therein, said movable electrode being provided with a concentrically positioned perfoi-ation, a tappet rod guided in saidperf'oration, said tappet rod being provided with a projecting portion adapted to engage and move said movable electrode upon,aetuation of said tappet rod, a spring normfally holding said tappet rod with said projection out of engagement with said movable electrode, and a spring normally holding said movable electrode in engagement withsaidfiXed electrode, said first mentioned spring being weaker than said second mentioned spring.

5. In a make and break spark plug, the combination of a base, a fixed electrode insulated thereon, a sleeve on said base, a movable electrode guided in said sleeve, a tappet rod controlled automatically by the speed and compression of the engine, said tappet combination of a fixed electrode, a movable rod being provided with a projecting portion adapted to engage and move said movable electrode upon actuation of said tappet rod, a spring normally holdin said t-appet rod with said projection out o? engagement with said movable electrode, and a spring normally holding said movable electrode in engagement with said fixed electrode, Said first mentioned spring being weaker than said second mentioned spring.

6. In a make and break spark plug, the combination of a base, a fixed electrode insulated thereon, a sleeve on said base, a movable electrode guided in said sleeve,l a cap on said movable electrode, a perforated casing on said base, aspring between the cap on the movable electrode and said casing, a tappet rod, a cap on said tappet rod, a spring between the said cap on said tappet rod and the perforated casing, said tappet rod being provided with a projecting portion adapted to engage and move said movable'eleotrode upon actuation of said tappet rod, a spring normally holding said tappet rod vwith said projection out of engagement with'said movable electrode, and a spring normally holding said movable electrode in engagement with said fixed electrode, said first mentioned spring being weaker than said second mentioned spring.

7. In a make and break spark plug, theA combination of a base, a fixed electrode insulated thereon, a sleeve on said base, a movable electrode guided in said sleeve, a cap on said movable electrode, a perforated casing on said base, a str'on spring having a tension corresponding to t e middle value of the compression pressure between the cap on the movable electrode and the said casing, a

tappet rod, a cap on said tappet rod, a spring of less tension than said first mentioned `spring between said cap on said tappet rod and t 1o perforated casing, said tappet rod being provided with a projecting portion adapted to engage and move said movable electrode upon actuation of said tappetrod,a, spring normally holding said tappet rod with said projection out of engagement with said movable electrode, and a spring normally holding said movable electrode in engagement with said fixed electrode, said first mentioned spring being weaker than said second mentioned spring.

8. In a make and break spark plug, the combination of a base, a sleeve on said base, a perforated casing on said. sleeve, la fixed electrode, insulating rings between said fixed elect-rode a-nd base, a movable electrode, a cap on said movable electrode, a strong spring between said cap and said perforated casing, packing means between said movable electrode and said sleeve, a.tappet rod concentric with said movable electrode, said tappet rod being provided with a projecting portion adapted to engage and move said movable electrode upon actuation of said tappet rod, a spring normally holding said -tappet rod with said projection out of en.-

gagement with said movable electrode, and a spring normally holding said movable elecfrode in engagement with said fixed electrode, said first mentioned spring being weaker than said second mentioned spring.

9. In a make and break spark plug, the combination of a base, a sleeve on said base, a conical seating` on said sleeve, a perforated casingon said sleeve, a fixed electrode, insulating rings between said fixed electrode and base, a movable electrode, a cap on said movable electrode, a strong spring between said cap and said perforated casing, a conical seating on saidV movable electrode adapted to engage with the conical seating on said sleeve during the sparking operation, a tappet rod concentric with said movable electrode, said tappet rod being provided with a projecting portion adapted to engage and move said movable electrode upon actuation of said tappet rod, a spring normally holding said tappet rod with said projection out 'of engagement with said movable electrode, and a spring normally holding said movable electrode in engagement with said fixed electrode, said first mentioned spring being weaker than said second mentioned spring.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

GUSTAV NAGEL. Witnesses:

RUDOLF WALTERs, ERNEST ENTENMANN. 

